I am going to create a getfeedback custom object (was trying to avoid this), and create a custom field in Marketo that pulls Salesforce Lead ID. Then use that field as a token, and see what's next from there.

Track who clicked on the getfeedback hyperlink in email sent from Marketo

Track who completed the getfeedback survey through an activity log, so I can:

suppress those who have completed the survey from a smart campaign which keeps deploying emails to remind people to fill out the survey

score the form fill activity (I will add this trigger or attribute to the already exists smart list under the "survey-filled" behavior scoring token)

What I have tried:

Embed a CTA button hyperlinked to the specific getfeedback survey in an email going out from Marketo to a test lead. I used

http://www.getfeedback.com/r/OwngxVZI/?Email={{Lead.Email Address}}. And I did go through the process of opening the emai;, clicking on the button, opening the getfeedback survey on getfeedback, completing the survey, and filling out the last question which asked for the lead's email address.

What didn't happen:

The lead's activity log only shows the opening of the email, and the clicking of the link. But it doesn't show rather the prospect completed the survey.

On why I came to the conclusion of creating a getfeedback CO on Salesforce - it's one of the suggestions from getfeedback. Although it's not clear it is an absolute step to make the activity log appeared in Marketo. I am going to give it a try.

If you're running surveys and you need to track answers in Marketo maybe Survicate would be the good alternative for you, since it has direct integration with Marketo and is the official Marketo's LaunchPoint partner. Scoring and segmenting your prospects would be easier. You can see your survey feedback in context with your prospect and customer data. There are also other survey tools with direct Marketo integration - check out LaunchPoint.